// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE

(function(mod) {
  if (typeof exports == 'object' && typeof module == 'object')
    // CommonJS
    mod(require('../../lib/codemirror'));
  else if (typeof define == 'function' && define.amd)
    // AMD
    define(['../../lib/codemirror'], mod);
  // Plain browser env
  else mod(CodeMirror);
})(function(CodeMirror) {
  'use strict';

  CodeMirror.defineMode('fcl', function(config) {
    var indentUnit = config.indentUnit;

    var keywords = {
      term: true,
      method: true,
      accu: true,
      rule: true,
      then: true,
      is: true,
      and: true,
      or: true,
      if: true,
      default: true,
    };

    var start_blocks = {
      var_input: true,
      var_output: true,
      fuzzify: true,
      defuzzify: true,
      function_block: true,
      ruleblock: true,
    };

    var end_blocks = {
      end_ruleblock: true,
      end_defuzzify: true,
      end_function_block: true,
      end_fuzzify: true,
      end_var: true,
    };

    var atoms = {
      true: true,
      false: true,
      nan: true,
      real: true,
      min: true,
      max: true,
      cog: true,
      cogs: true,
    };

    var isOperatorChar = /[+\-*&^%:=<>!|\/]/;

    function tokenBase(stream, state) {
      var ch = stream.next();

      if (/[\d\.]/.test(ch)) {
        if (ch == '.') {
          stream.match(/^[0-9]+([eE][\-+]?[0-9]+)?/);
        } else if (ch == '0') {
          stream.match(/^[xX][0-9a-fA-F]+/) || stream.match(/^0[0-7]+/);
        } else {
          stream.match(/^[0-9]*\.?[0-9]*([eE][\-+]?[0-9]+)?/);
        }
        return 'number';
      }

      if (ch == '/' || ch == '(') {
        if (stream.eat('*')) {
          state.tokenize = tokenComment;
          return tokenComment(stream, state);
        }
        if (stream.eat('/')) {
          stream.skipToEnd();
          return 'comment';
        }
      }
      if (isOperatorChar.test(ch)) {
        stream.eatWhile(isOperatorChar);
        return 'operator';
      }
      stream.eatWhile(/[\w\$_\xa1-\uffff]/);

      var cur = stream.current().toLowerCase();
      if (
        keywords.propertyIsEnumerable(cur) ||
        start_blocks.propertyIsEnumerable(cur) ||
        end_blocks.propertyIsEnumerable(cur)
      ) {
        return 'keyword';
      }
      if (atoms.propertyIsEnumerable(cur)) return 'atom';
      return 'variable';
    }

    function tokenComment(stream, state) {
      var maybeEnd = false,
        ch;
      while ((ch = stream.next())) {
        if ((ch == '/' || ch == ')') && maybeEnd) {
          state.tokenize = tokenBase;
          break;
        }
        maybeEnd = ch == '*';
      }
      return 'comment';
    }

    function Context(indented, column, type, align, prev) {
      this.indented = indented;
      this.column = column;
      this.type = type;
      this.align = align;
      this.prev = prev;
    }

    function pushContext(state, col, type) {
      return (state.context = new Context(
        state.indented,
        col,
        type,
        null,
        state.context,
      ));
    }

    function popContext(state) {
      if (!state.context.prev) return;
      var t = state.context.type;
      if (t == 'end_block') state.indented = state.context.indented;
      return (state.context = state.context.prev);
    }

    // Interface

    return {
      startState: function(basecolumn) {
        return {
          tokenize: null,
          context: new Context((basecolumn || 0) - indentUnit, 0, 'top', false),
          indented: 0,
          startOfLine: true,
        };
      },

      token: function(stream, state) {
        var ctx = state.context;
        if (stream.sol()) {
          if (ctx.align == null) ctx.align = false;
          state.indented = stream.indentation();
          state.startOfLine = true;
        }
        if (stream.eatSpace()) return null;

        var style = (state.tokenize || tokenBase)(stream, state);
        if (style == 'comment') return style;
        if (ctx.align == null) ctx.align = true;

        var cur = stream.current().toLowerCase();

        if (start_blocks.propertyIsEnumerable(cur))
          pushContext(state, stream.column(), 'end_block');
        else if (end_blocks.propertyIsEnumerable(cur)) popContext(state);

        state.startOfLine = false;
        return style;
      },

      indent: function(state, textAfter) {
        if (state.tokenize != tokenBase && state.tokenize != null) return 0;
        var ctx = state.context;

        var closing = end_blocks.propertyIsEnumerable(textAfter);
        if (ctx.align) return ctx.column + (closing ? 0 : 1);
        else return ctx.indented + (closing ? 0 : indentUnit);
      },

      electricChars: 'ryk',
      fold: 'brace',
      blockCommentStart: '(*',
      blockCommentEnd: '*)',
      lineComment: '//',
    };
  });

  CodeMirror.defineMIME('text/x-fcl', 'fcl');
});
